Administratoe of



UNITED STATES PATENT OFFICE.

ADDISON E. HALEY, OF KENNEBUNK, MAINE, ADMINISTRATOR OF THOMPSON HANNA, DECEASED.

PROCESS OF MANUFACTURING PARCHMENTIZED PAPER AND PAPER-BOARD.

SPECIFICATION forming part of Letters Patent No. 510,422, dated December 12, 1893.

Original application filed December 6, 1892, Serial No. 454,271. Divided and this application filed April 8, 1893. Serial No.

469,608- (No specimens.)

To aZZ whom it may concern.-

Be it known that THOMPSON HANNA, deceased, late a resident of Kennebunk, in the county of York and State of Maine, did invent during his life-time a new and useful Process of Manufacturing Parchmentized Paper and Paper-Board, of which the following is aspecification.

This invention relates to the manufacture of that class of goods known to the trade as leatheroid, vulcanized fiber, and other coined names, which are made by treating cellulose (usually in the form of paper) with chloride of zinc, sulphuric acid or other parchmentizing agents; and in referring to any of such products herein reference is had to all, and in using the Word paper reference is had to cellulose, whether in the form of paper or otherwise.

The object of this invention is to obtain a more efficient action of the chemicals used in such manufacture upon the paper being treated than is practicable by former methods, particularly when using extra thick or hard paper.

It is well known that, if paper used for parchmentizing is too thick or too hard, it will not properly absorb the compound, but will only take it upon the surface, and when soaked in water will separate into two sheets, one side of each of which will not be treated. It has been found by Mr. HANNA that if paper so thick and hard that it could not be successfully treated in the usual manner, is first run through a bath of acid too dilute to properly parchmentize it, the compound will be absorbed through the entire thickness of the paper, and that if it is then put in a bath sufficiently strong to parchmentize it, the strong compound will follow the weaker and the whole sheet will be properly acted upon, and it has also been found that there is advantage obtained in treating any sheet, even if of the ordinary thickness, with these several baths, and therefore the paper is first run through a weak bath, and then through one or more of increasing strength, the last being the strongest bath used, and after that it can be wound directly upon the forming roll if it is desired to form a board of increased thickness.

This invention is not confined to any definite number of baths or to any exact strength in either, as the baths may be greater or less in number and the difference in strength of the several baths may be varied according to the paper to be used and the results required.

In another application filed Decemberv 6, 1892, Serial No. 454,271,0f which this present application is a division, a process of manufacturing parchmentized paper-board is described and claimed, which is apparently merely the reverse of the process herein described and claimed, but the two processes are used for distinctly different purposes and different results are produced.

The process herein described and claimed is used, as set forth, for treating extra thick or extra hard paper, in order to insure the parchmentizing of the center of the sheet, which could not successfully be done by the process described in the prior application, above cited, which process is used when thin soft paper is employed, and effectually prevents the excessive action of the chemicals at the center of the board, which often results when thick boards are made up before the sheets have been soaked in Water to remove, or check the action of the chemicals in the ordinary manner.

What is claimed is- '1. The process of manufacturing parchmentized paper by passing the paper through a plurality of baths of parchmentizing liquid of which that through which the paper is first passed is weaker than that through which it is passed last.

2. The process of manufacturing parchmentized paper boards which consists in passing paper successively through a pluralityof baths of parchmentizing liquid of gradually increasing strength and then uniting several layers of the paper by pressure to form the required thickness.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this 28th day of March, A. D. 1893.

ADDISON E. HALEY, As administrator of the estate of said Thompson Hanna.

Witnesses:

GEORGE BONSER, FRANK W. BONSER. 

